Within the shipping industry exists a segment of transportation that focuses on less-than-truckload (LTL) freight loads, which can vary from a single item to a nearly full truckload. To transport freight originating from a common origin destined for multiple locations around the country or region, LTL carriers often employ a hub-and-spoke network of terminals.
Once freight is picked up, it is brought back to a facility where it is transferred across a dock (a process commonly referred to as “cross-docking”). This process typically involves manually unloading the load (or portion thereof) from one trailer and loading it onto another. An system for improving cross-dock operations is described in U.S. Pat. No. 9,367,827, issued Jun. 14, 2016, the entire content of which is hereby incorporated by reference in its entirety.
In recent years, there have been many improvements in warehouse operations. Specifically, large e-commerce retailers and shipping services have begun to use automated guided vehicles (AGVs) to move freight around warehouses. Typically, these AGVs are lower-cost devices that are designed to move freight placed upon them from a first location to a second location in the warehouse. These AGVs use a simple navigation method using markers and have basic collision sensors to avoid bumping into other AGVs.
However, these AGVs are typically not suited for cross-dock operations, especially in an LTL environment. First, in a cross-dock operation, an AGV may need to convey an entire movable platform (MP) which can weigh up to 24,000 pounds (or more). AGVs currently being used in most warehouses can typically only convey a few hundred pounds at most. Further, most current AGVs can only move in a grid-like pattern whereas cross-dock operations require much more advanced collision avoidance systems because manual workers may also be present.
Additionally, as will be described later, the AGVs may need to perform a variety of functions such as moving MPs, moving decks, and/or moving individual pieces of freight. Current AGVs and cross-dock systems are not equipped to handle and/or calculate these types of moves. What is needed is a cross-dock management system capable of effectively using AGVs to supplement or entirely replace manual moves in a cross-dock environment. Such a cross-dock system must be highly adaptable to handle exceptions, such as AGV recharging or maintenance, and should enable cross-dock operations to be extended to operate 24 hours a day, seven days a week